Answer :
Final answer:
A dial indicator is the correct tool for checking a pilot-type valve stem for stretch, due to its ability to measure small movements with high precision.
Explanation:
To check the stem on a pilot-type valve for stretch, the appropriate tool would be a dial indicator. A dial indicator can measure small distances or movements with precision, which is essential when verifying the integrity of valve stems for any signs of stretching or elongation.
A micrometer could be used for dimensional measurements, a thread pitch gauge for measuring the pitch or lead of a screw thread, and a feeler gauge for measuring gap widths, but none of these tools are specifically designed for detecting stretch in a valve stem like a dial indicator.
